HUMUS CONDITION OF SOILS IN NORTHERN KAZAKHSTAN UNDER SIDRAL PRESIDENTS OF WHEAT (ON SHORT-FARM CROP)
Keywords:green manure crops, crop rotations, humus, carbon, labile humus, humic acids, fulvic acids, soil fertility, humus reserves in the soil.
The humus content on the rapeseed variety varied from 2.81 to 3.13%, “mustard wheat 2.16 - 3.03% and wheat in a pea-oat mixture 2.53 - 2.98%. Labile organic matter was the most responsive to changing the placement of wheat on options. Dependencies between the depth of the horizon and the content of labile humus in a layer of 0–30 cm were not recorded for crop rotation. The highest content of labile humus is marked on the variant «wheat in a pea-oat mixture», the smallest “wheat in mustard.” The highest content of humic acids in the 0-10cm layer was recorded on the variant «wheat in a pea-oat mixture», the smallest «wheat in mustard». These soils have humate and fulvatno-humate type Cga: Cfa> 1. At the same time, the level of fulvic acids between the variants of crop rotation was at the same level - 0.21- 0.22%. The studied soils under crop rotations were characterized by low humus reserves and an average degree of humification